Is it still worth playing even though it doesn't have controller support (unless that's been changed)? I have enjoyed Grim Dawn, Torchlight 2 and Spiderwebs games with mouse but do prefer a gamepad mostly.

Listening to the latest Larian interview they still are working on several additions to this game (like better AI, more companions, etc.).Further more there are some more or less serious bugs still present, likewise game mechanics could need some optimization (extreme heat on capable machines).

If you can live having that: yes, go on and purchase now.Waiting until maybe the end of August might help in not seeing that many bug fixes.

Yes definitely, in every sense. But there is a few caveat. You must be ok with turn base combat (its implementation is nifty and doesn't bog you down, unless you got in way over your head :P), it is top down isometric view (although very forgiving and unlimited panning helps a lot) and at this time, there are a few non gaming breaking bugs (as usual :P)